My 97 w210 has lights that randomly turn off and come on again, they may work ok for months and then have a spell over a few days where they go off and instantly come back on or do not come on when switch is operated.

I have aftermarket sidelight l.e.d bulbs which set the bulb warning off when lights are switched, so when the lights misbehave the dash will chime in and let me know.
When they do go out main beam (high) still works by pulling stalk back as normal.

Plenty of vids on Youtube concerning this.